Effect of urgent surgery within 8 hours compared to surgery between 8 and 24 hours on perioperative complications and neurological prognosis in patients older than 70 years with cervical spinal cord injury: a propensity score-matched analysis.

OBJECTIVE: This study aimed to investigate the effect of surgery within 8 hours on perioperative complications and neurological prognosis in older patients with cervical spinal cord injury by using a propensity score-matched analysis. METHODS: The authors included 87 consecutive patients older than 70 years who had cervical spinal cord injury and who had undergone posterior decompression and fusion surgery within 24 hours of injury. The patients were divided into two groups based on the time from injury to surgery: surgery within 8 hours (group 8 hours) and between 8 and 24 hours (group 8-24 hours). Following the preliminary study, the authors established a 1:1 matched model using propensity scores to adjust for baseline characteristics and neurological status on admission. Perioperative complication rates and neurological outcomes at discharge were compared between the two groups. RESULTS: Preliminary analysis of 87 prematched patients (39 in group 8 hours and 48 in group 8-24 hours) revealed that the motor index score (MIS) on admission was lower for lower extremities (12.3 ± 15.5 vs 20.0 ± 18.6, respectively; p = 0.048), and total extremities (26.7 ± 27.1 vs 40.2 ± 30.6, respectively; p = 0.035) in group 8 hours. In terms of perioperative complications, group 8 hours had significantly higher rates of cardiopulmonary dysfunction (46.2% vs 25.0%, respectively; p = 0.039). MIS improvement (the difference in scores between admission and discharge) was greater in group 8 hours for lower extremities (15.8 ± 12.6 vs 9.0 ± 10.5, respectively; p = 0.009) and total extremities (29.4 ± 21.7 vs 18.7 ± 17.7, respectively; p = 0.016). Using a 1:1 propensity score-matched analysis, 29 patient pairs from group 8 hours and group 8-24 hours were selected. There were no significant differences in baseline characteristics, neurological status on admission, and perioperative complications between the two groups, including cardiopulmonary dysfunction. Even after matching, MIS improvement was significantly greater in group 8 hours for upper extremities (13.0 ± 10.9 vs 7.8 ± 8.3, respectively; p = 0.045), lower extremities (14.8 ± 12.7 vs 8.3 ± 11.0, respectively; p = 0.044) and total extremities (27.8 ± 21.0 vs 16.0 ± 17.5, respectively; p = 0.026). CONCLUSIONS: Results of the comparison after matching demonstrated that urgent surgery within 8 hours did not increase the perioperative complication rate and significantly improved the MIS, suggesting that surgery within 8 hours may be efficient, even in older patients.

The relationship between spinal alignment and activity of paravertebral muscle during gait in patients with adult spinal deformity: a retrospective study.

BACKGROUND: Spinal alignment in patients with adult spinal deformity (ASD) changes between rest and during gait. However, it remains unclear at which point the compensated walking posture breaks down and how muscles respond. This study used time-synchronized electromyography (EMG) to investigate the relationship between dynamic spinal alignment and muscle activity during maximum walking duration to reveal compensation mechanisms. METHODS: This study collected preoperative three-dimensional gait analysis data from patients who were candidates for corrective surgery for ASD from April 2015 to May 2019. We preoperatively obtained dynamic spinal alignment parameters from initiation to cessation of gait using a motion capture system with time-synchronized surface integrated EMG (iEMG). We compared chronological changes in dynamic spinal alignment parameters and iEMG values 1) immediately after gait initiation (first trial), 2) half of the distance walked (half trial), and 3) immediately before cessation (last trial). RESULTS: This study included 26 patients (22 women, four men) with ASD. Spinal sagittal vertical axis distance during gait (SpSVA) increased over time (first vs. half vs. last, 172.4 ± 74.8 mm vs. 179.9 ± 76.8 mm vs. 201.6 ± 83.1 mm; P < 0.001). Cervical paravertebral muscle (PVM) and gluteus maximus activity significantly increased (P < 0.01), but thoracic and lumbar PVM activity did not change. Dynamic spinal alignment showed significant correlation with all muscle activity (cervical PVM, r = 0.41-0.54; thoracic PVM, r = 0.49-0.66; gluteus maximus, r = 0.54-0.69; quadriceps, r = 0.46-0.55) except lumbar PVM activity. CONCLUSION: Spinal balance exacerbation occurred continuously in patients with ASD over maximum walking distance and not at specific points. To maintain horizontal gaze, cervical PVM and gluteus maximus were activated to compensate for a dynamic spinal alignment change. All muscle activities, except lumbar PVM, increased to compensate for the spinal malalignment over time.

Postoperative Changes in Resting State Functional Connectivity and Clinical Scores in Patients With Cervical Myelopathy.

OBJECTIVE: Resting state functional magnetic resonance imaging (rs-fMRI) is a technique for the analyzing functional connectivity (FC) between anatomically distant brain regions at rest. The purpose of this study was to analyze postoperative FC changes in patients with compression cervical myelopathy, to evaluate their relationship with clinical scores, and to examine the changes in spinal cord function associated with brain networks. METHODS: This prospective study comprised 15 patients with cervical myelopathy who underwent planned surgery. Rs-fMRI was performed preoperatively and 6 months postoperatively with the similar protocol. Clinical function was assessed by the Japanese Orthopedic Association (JOA) score, the Japanese Orthopedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ), and the numerical rating scale (NRS). We performed a seed-based analysis, and identified the networks that changed significantly following surgery. Furthermore, we performed a correlation analysis to compare the postoperative changes in FC with clinical scores. RESULTS: Five FCs were significantly increased postoperatively; 4 were between the sensorimotor network (SMN) and other regions. We observed a significant correlation between the FC of the right SMN and the left precentral gyrus with the JOA score, the left SMN with the JOACMEQ for upper extremity function, and the left postcentral gyrus with the NRS. CONCLUSIONS: The reorganization of the sensorimotor cortex occurred postoperatively in patients with compression cervical myelopathy. In addition, each change in FC was significantly correlated with the clinical scores, thus indicating an association between the recovery of spinal cord function and plastic changes in the sensorimotor cortex.

Evaluation of dynamic spinal alignment changes and compensation using three-dimensional gait motion analysis for dropped head syndrome.

BACKGROUND CONTEXT: Dynamic kinematic evaluation of spino-pelvic alignment during gait using three-dimensional (3D) motion analysis has been proposed for adult spinal thoracolumbar deformity. That is because conventional full-spine radiographs cannot be used to evaluate dynamic factors. However, dynamic changes in spino-pelvic alignment during gait for dropped head syndrome (DHS) have not been studied using this approach. PURPOSE: This study aimed to assess the dynamic changes in spinal-pelvic alignment during gait in patients with DHS using 3D motion analysis. STUDY DESIGN: Retrospective review of collected radiographic and kinematic data. PATIENT SAMPLE: Nineteen DHS patients with neck pain and/or anterior gaze disturbance. OUTCOME MEASURES: Static spino-pelvic radiological alignment, dynamic spino-pelvic kinematic parameters and electromyogram (EMG) data. METHODS: Center of gravity of the head - C7 sagittal vertical axis (CGH-C7 SVA), C2-C7 SVA, T1 slope; cervical lordosis (CL), C7SVA, thoracic kyphosis (TK), lumbar lordosis (LL), pelvic tilt (PT) and pelvic incidence (PI) were assessed using full-spine radiographs in a standing position to assess static spino-pelvic alignment. The 3D gait motion analysis was conducted during gait. Dynamic kinematic parameters were divided into spinal segments: cervical (C-), thoracic (T-), lumbar (L-) and pelvis (P-). Each spinal segment coronal angle to the pelvic angle, each spinal segment sagittal angle to the pelvic angle and pelvic sagittal angle to the horizontal axis were assessed as dynamic spino-pelvic kinematic parameters. Trunk and lower limb muscle activity during gait were assessed using wireless surface EMG analysis. Dynamic spino-pelvic kinematic variables and muscle activity were compared between the first walking lap and the final lap during gait analysis. The change in dynamic kinematic parameters was correlated with static radiological alignment and electromyographic muscular activity change. RESULTS: Cervical and thoracic anterior tilt increased significantly after an extended period of walking, indicating that dropped head worsened during gait. An increase of cervical anterior tilt during walking was significantly associated with decreased muscle activity in the cervical paraspinal muscles (r=-0.463, P<.05) and latissimus dorsi (r=-0.763, p<.01). Furthermore, significant correlations were found between a change in thoracic sagittal angle to pelvic angle and C7SVA (r=0.683, p<.01) and LL (r=-0.475, p<.05). This means that a larger C7SVA and smaller LL were associated with increased thoracic anterior tilt during gait. CONCLUSIONS: The 3D motion analysis for DHS showed that cervical and thoracic anterior tilt significantly increased after extended walking, resulting in worsening of dropped head. Decreased muscle activity of the neck extensor muscles during gait suggests insufficient neck extensor muscle endurance, which was associated with increased cervical anterior tilt. A greater increase in the thoracic anterior tilt during gait was found in DHS patients with a larger C7SVA and smaller LL due to insufficient thoracolumbar compensation for the dropped head. Correction of the cervical spine alone would not be sufficient to improve dropped head in cases with increased thoracic anterior tilt during gait. The results suggest that C7SVA and LL are crucial parameters in the surgical strategy for DHS.